I have some sad news for you guys, the HS 20mm cannon could easily kill even a Tiger I through its deck armor. The armor on the deck of the Panzer IV is about 15mm, on the Tiger I it is 10mm. If you hit the tank in the front or one the side (or the rear of the Tiger I) the HS 20mm should bounce off, but the deck WILL be penetrated. The purpose of the side walls on the Panzer IV modeled here is to give the deck more protection from straffing fighters-bombers.
The problem is that the plane set does not reflect historical reality. Imagine if HTC limited the number of times that a plane could be flown per tour. Say, 2 or 3 times the number of aircraft built. That way the 1C could only fly 800 to 1200 sorties, the Typhoon could fly 6000 to 9000, the P-51D could fly about 25000 to 37000, B-17G about 16000 to 24000, Spitfire MkIX about 11000 to 16500 and the C.202 could fly about 3000 to 4500 sorties. These are example numbers. Each side (Knights, Rooks, Bishops) would get their own sortie counter. This way, aircraft would be limited in some fashion, by their historical numbers. This would also force the employment of older airframes. Each side would want to figure out how to employ their Bf-109F and Spitfire MkVb airframes so that the jobs that those old aircraft could do would not absorb the precious missions that the F4U-1C could fly, it being needed for the missions that only it is capable of flying.
Sisu